The field of tissue engineering has the goal of regenerating or replacing tissue lost to disease or injury by implantation of cultured cells. Most cells that are useful for this purpose are attachment dependant, meaning that they will not survive unless bound to some type of solid surface. Within the human body attachment-dependant cells are attached to a natural scaffold material known as the extracellular matrix (ECM). Thus a tissue-engineered implant typically comprises cells that have been seeded on an artificial scaffold.
Some recent advances in the field of tissue engineering have focused on synthetic polymeric materials that are compatible with cell attachment. Since many synthetic polymerizable materials, e.g., poly(hydroxyethyl methacrylate) (pHEMA) are cell repellant, such materials may typically incorporate biopolymers such as collagen, laminin, fibronectin, hyaluronic acid, or other proteins and/or polysaccharides calculated to enhance cell attachment. Alternatively, specific cell binding moieties such as arginine-glycine-aspartic acid (RGD) peptide motifs may be grafted onto the hydrogel to confer cell attachment potential.
Keratins found in human and other animal hair have attracted interest as a potential biomaterial. Keratins, however, are tightly bound to each other so that recovering keratin biomolecules is difficult.